PHYSICO-CHEMICAL CONDITIONS AND PHYTOPLANKTON DIVERSITY OF MARJAD BAOR OF KALIGANJ UPAZILA, JHENAIDAH, BANGLADESH By Md. Ferdous Alam

INTRODUCTION

I ntroduction Water is the most vital element among the natural resources, and is crucial for the survival of all living organisms. “Marjad Baor” is a large biologically significant Oxbow lake (NCS, 1991) and declared as an Ecological Critical Area by DoE in It is loosing it’s area and natural condition because of anthropogrnic activities. Agricultural practices are increasing day by day at the surrounding area. “Marajd Baor” is the main source of income of the adjacent fisherman community and it possess a wide range of biodiversity.

A ims and Objectives of the Study The main objective of the study is to determine the water quality of the “Marjad Baor through the analysis of its physico-chemical conditions, phytoplankton diversity and their interrelationships. The present investigation has been taken to achieve the following specific objectives: To find out the physico-chemical conditions of the Marjad baor. To find out the diversity and abundance of phytoplankton in the Marjad Baor. To find out the relationship between physico-chemical conditions and phytoplankton diversity in the Marjad Baor.

MATERIALS AND METHODS

M aterials and Methods Location of the Study Area Present study was conducted at the Marjad Baor, the largest Baor of Bangladesh which is under Kashthabhanga Union of Kaliganj Upazilla. It is situated at the north of Chaugachha Upazila under Jessore district and at the south – west part of Kaliganj Upazila under Jhenaidah district. The total area of Marjad Baor is about 253 hectares which is 25 km apart from Kaliganj Upazila. It is located between the latitude of ′27.08″ N to ′40.08″ N and between the longitudes of ′08.24″ E to ′51.78″ E.

Figure 1: Map of the study area

Figure 2: Sampling spot 1 – Hizoltola Ghat Figure 3: Sampling spot 2 – Nalvanga Ghat

Figure 4: Sampling spot 3 – Middle of the Baor Figure 5: Sampling spot 4 – Mirzapur

Study period Country boats were used to collect both water and phytoplankton samples. Water samples were collected from each spot at a depth of cm below the water surface. The phytoplankton samples were collected from four spots, with plankton net (1 meter long, diameter of 22 cm) of No. 22 silk bolting cloth (Mesh size mm). Collection of water and phytoplankton samples The present study was carried out from January, 2010 to March, The samples were collected for three terms with an interval of one month.

Table 1: List of analyzed parameters Category of parametersName of the parametersPlace of analysis Physical parameters Water Temperature and Air Temperature Field analysis Transparency Total Dissolved Solid (TDS) Electrical Conductivity (EC) Chemical parameters Hydrogen Ion Concentration (pH) Dissolved Oxygen (DO) Free Carbon-Dioxide (CO 2 ) Biological Oxygen Demand ( BOD 5 ) Laboratory analysis Carbonate Alkalinity (CO 3 - ) Bicarbonate Alkalinity (HCO 3 - ) Calcium Hardness (Ca 2+ ) Magnesium Hardness (Mg 2+ ) Total Hardness Chloride (Cl - ) Phosphate (PO 4 3- ) Nitrate (NO 3 - )

Table 2: Analytical methods used to determine the Baor water chemistry and phytoplankton abundance ParametersUnitMethods /InstrumentsReferences Temperature oCoCCentegrade Mercury Thermometer Ramesh and Anbu, 1996 pH-Microprocessor p H meter (HANNA instruments, pH 211) ECµs/cmTDS meter (H1-9635, portable water proof Multirange Conductivity/TDS meter, HANNA) TDSppmTDS meter (H1-9635, portable water proof Multirange Conductivity/TDS meter, HANNA) DOmg/lWinckler’s method BOD 5 mg/lWinckler’s method Free CO 2 mg/lWelch method Ca 2+ mg/lTitrimetric method Mg 2+ mg/lTitrimetric method Cl - mg/lTitrimetric method HCO 3 - mg/lWelch method PO 4 3- ppmAscorbic acid method (Thermospectronic, UV-visible Spectrophotometers, Helios ) NO 3 - ppmUltraviolet spectrophotometric screening method (Thermospectronic, UV-visible Spectrophotometers, Helios ) PhytoplanktonUnit/lElectron Microscope and Counting CellApha

Calculation for phytoplankton counting The abundance of phytoplankton groups were calculated according to the following formulae (Welch, 1948). Where, N = Number of phytoplankton per liter of original water. a = Average number of plankton in per all counts in the counting cell. c = Volume of original concentration in ml. L = Volume of water passed through the net.

RESULTS AND DISCUSSION

Table 3: Physico-chemical conditions and phytoplankton abundance of Marjad Baor - = Not Detected ParameterUnitMean value (January–March, 2010) Spot - 1Spot – 2Spot – 3Spot - 4 Air temperature oCoC30.33± ±2.0529±2.4528±2.45 Water temperature oCoC27± ± ± ±3.30 Transparencycm50.67± ± ± ±2.87 ECµs/cm230.67± ± ± ±1.63 TDSmg/l109.5± ± ± ±0.66 pH7.52± ± ± ±0.15 DOmg/l8.23± ± ± ±0.33 BOD 5 mg/l1.3± ± ± ±0.21 Free CO 2 mg/l0.07± ± ± ±0.02 CO 3 - mg/l---- HCO 3 - mg/l142.9± ± ± ±1.60 Ca 2+ mg/l ± ± ±3.32 Mg 2+ mg/l19.77± ± ±2.11 Total hardnessmg/l87.90± ± ± ±5.15 Cl - mg/l7.70± ± ±0.82 PO 4 3- ppm0.094± ± ± ±0.006 NO 3 - ppm1.65± ± ± ±0.01 PhytoplanktonUnit/l43,416±8,51036,633±8,68448,216±7,10056,900±9,738 = Lowest Value = Highest Value

ClassSpeciesTotal abundance (units/l) Spot - 1Spot - 2Spot - 3Spot - 4 Cyanophyceae Anabaena sp Nostoc sp Oscillatoria sp Lyngbya sp Gloeocapsa sp Aphanocapsa sp Merismopedia sp Aphanothece sp Nodularia sp Sytonema sp Microchaete sp Chlorophyceae Stigeoclonium sp Uronema elongatum sp Chaetophora sp Rhizoclonium sp Cladophora sp Pediastrum sp Closterium sp Cosmarium sp Oedogonium sp.3790 Staurastrum sp Myrmecia sp Bacillariophyceae Synedra sp Fragilaria sp Melosira sp Navicula sp Pinnularia sp Gyrosigma sp Cymbella sp Cybetta sp.5035 Nitzschia sp Euglenophyceae Euglena sp Phacus sp Trachelomonas sp Total1,30,2501,09,9001,44,6501,70,700  Highest abundant group  2 nd highest abundant group  3 rd highest abundant group Table 4: Diversity and abundance of phytoplankton species

Figure 6: Percentage composition of phytoplankton classes in Spot - 1 Figure 7: Percentage composition of phytoplankton classes in Spot - 2

Figure 8: Percentage composition of phytoplankton classes in Spot - 3 Figure 9: Percentage composition of phytoplankton classes in Spot - 4

Parameters Phytoplankton Spot - 1Spot - 2Spot - 3Spot - 4 Air temperature ( o C)--1.0**1.0* Water temperature ( o C) *- Transparency (cm) EC ( µ s/cm) * TDS (mg/l)1.0** pH DO (mg/l) BOD 5 (mg/l)-0.998* Free CO 2 (mg/l)-0.998* HCO 3 - (mg/l) ** Ca 2+ (mg/l) * Mg 2+ (mg/l) Total Hardness (mg/l) Cl - (mg/l) PO 4 3- (ppm) NO 3 - (ppm)1.0**-0.999*- Table 5: Relationship between different physico-chemical factors and phytoplankton abundance ‘-’negative relationship ‘*’ significant value

Parameters Positively SignificantNegatively Significant Air temperature ( o C)Water temperature, EC, NO 3 -, Phytoplankton pH, DO, HCO 3 -, Ca 2+,Total Hardness Water temperature ( o C)Air temperature, DO, NO 3 -, Phytoplankton TDS, DO, BOD 5, Ca 2+ Transparency (cm)HCO 3 - EC EC ( µ s/cm) pH, HCO 3 -, PhytoplanktonTransparency, DO TDS (mg/l)BOD 5, Mg 2+, NO 3 -, PhytoplanktonDO pHECDO, Mg 2+, Total Hardness DO (mg/l)Water temperature, Free CO 2, Ca 2+, Cl - EC, TDS, BOD 5 BOD 5 (mg/l)TDS, Free CO 2, PhytoplanktonWater temperature, Mg 2+, DO Free CO 2 (mg/l)DO, BOD 5, Cl -, Phytoplankton-- HCO 3 - (mg/l)EC, Transparency, Ca 2+, Mg 2+, Total Hardness Air temperature Ca 2+ (mg/l)DO, HCO 3 -, PO 4 3- NO 3 -, Phytoplankton Mg 2+ (mg/l)TDS, Total Hardness, PO 4 3-, NO 3 - pH, BOD 5 Total Hardness (mg/l)PO 4 3- pH, NO 3 - Cl - (mg/l)DO, Free CO 2 -- PO 4 3- (ppm)Ca 2+, Mg NO 3 - (ppm)TDS, Mg 2+, PhytoplanktonCa 2+, Total Hardness Table 6: Significant relationship between different physico-chemical factors and phytoplankton abundance

ParametersunitsBangladesh standard Mean values of the parameters at different spotRemarks SP-1SP-2SP-3SP-4 Water temperature 0C0C Within the standard Transparencycm< Within the standard TDSppm≤ Within the standard EC µ s/cm Within the standard pH Within the standard BOD 5 mg/l Within the standard DOmg/l Within the standard Free CO 2 mg/l< Within the standard Total hardnessmg/l Below the standard except SP-2 Total Alkalinitymg/l Within the standard Ca 2+ mg/l Within the standard Mg 2+ mg/l Within the standard Cl - mg/l ≤ Within the standard PO 4 3- ppm < within the standard NO 3 - ppm≤ Within the standard Table 7: Comparison between Bangladesh standards for fish culture and measured values Source: Environmental protection agency report,

CONCLUSION

From the above study it can be said that the water of “Marjad Baor” is poorly alkaline and it is a eutrophic lake. The physico-chemical condition of the baor water is favorable for phytoplankton growth at this time. But some of the parameters are approaching to exceed the standard. Oscillatoria sp. was the dominant species in most of the spots than Anabaena sp. which may be the main sign of eutrophication. Addition of domestic wastes, agricultural runoff and other anthropogenic practices are changing the natural quality of water. If the ecological condition of Marjad Baor can not be restored as soon as possible a huge number of biological diversity will be in threatened condition. So, further study is needed for the better management of the “Marjad Baor”.

THANKS TO ALL